Ball and socket joint body for control cable terminals

ABSTRACT

A ball and socket joint body for terminals of control cables has a transverse passage with respect to the coupling of the cable with the terminal which forms two reciprocally opposed inlet mouths of freely choosable alternative use, and a central chamber for housing a ball with elastically deformable retaining and seat structure. The retaining and seat structure can comprise a sleeve provided with perimetral projections, or a first shock-absorbing sleeve and a second sleeve provided with coplanar sectoral projections or two &#34;U&#34;-shaped springs or a sleeve and two &#34;U&#34; shaped springs which traverse it.

BACKGROUND OF THE INVENTION

The present invention relates to a ball and socket joint body forcontrol cable terminals, which is generally applicable to control cablesfor the transmission of thrust-traction forces, which are usually knownas push-pull operating cables. More particularly, the ball and socketjoint body of the invention is applicable to terminals ofthrust-traction control cables generally used as a means of linkagebetween the gearbox and its operating shift lever in automobilevehicles.

Widely known in the art are many embodiments of thrust-traction controlcables which, basically consisting in a sheathed steel cable, areextensively used in the automobile industry as an articulated means oflinkage between an actuating control and its associated mechanism. Suchcontrol cables are provided at one of their ends with a terminal which,when coupled to the corresponding actuating control, forms a ballarticulation or ball and socket joint. Essentially, said articulationcomprises a ball and socket body and a ball, in which the ball andsocket body constituting the terminal is fixed to the corresponding endof the steel cable of the control cable by means of a rigid linkingpiece, such as an axially mounted metal rod, while the ball is fixed tothe actuating control. The ball and socket body comprises a housingdesigned to receive the ball with a close fit and in such a way thatonce the ball and socket body and the ball are coupled together, thecontrol cable is able to transmit thrust-traction forces along its axisfor any of the actuating control positions habitually used.

In the known embodiments of ball and socket joint bodies such as thosedescribed above, the means for coupling of the ball and socket jointbody with the ball consist, in summary, of a single opening made in theball and socket joint body to permit the insertion by pressure of theball into a spherical housing. In general, said coupling arrangementconstitutes a clear disadvantage, in that coupling of the control cablewith its corresponding actuating mechanism calls for prior positioningof the ball and socket joint body of the cable with respect to the ball.This disadvantage is accentuated in those cases in which the actuatingcontrol is formed by the gearbox gear shift lever; in this case, thepositioning of the ball and socket joint body of the terminal of thecontrol cable is generally only possible by rotating the control cableabout itself, which given the usual scale of said control cables,together with the difficulty of access to the ball of the lever,constitutes an operation by no means devoid of difficulties andrequiring in any case an execution time which increases fitting costs.

SUMMARY OF THE INVENTION

A ball and socket joint body of new structure and operation forterminals of control cables is made known hereby in order to provide asolution to the above-described disadvantages presented by the knownembodiments of terminals for control cables, which when coupled form aball or ball and socket joint.

The ball and socket joint body for terminals of control cables of theinvention is applicable to terminals of thrust-traction control cables,of the type made up of a sheathed steel cable, in which thecorresponding end of the steel cable has means for firm coupling thereofwith the terminal which, preferably, is made by injection of plasticmaterial and can adopt any configuration suitable to each specific caseof application, said coupling means consisting in an axially mountedmetal rod which is included in the terminal during manufacturing ofsame.

The ball and socket joint body for terminals of the invention ischaracterized in that it includes a passage arranged transversally withrespect to the longitudinal axis of the means of coupling of the steelcable, in which the transverse passage has two reciprocally opposedinlet mouths, of freely choosable alternative use, situated on eitherside of the ball and socket joint body, and arranged in centred positiona chamber of generally cylindrical shape for housing the ball linked tothe actuating control and in which are provided elastically deformableretaining means and seat so designed that passage of the ball throughone or other of the inlet mouths is implemented by double elasticdeformation of the retaining and seat means.

According to a first embodiment, the retaining and seat means arecharacterized in that they comprise, coaxially arranged with respect tothe transverse passage and fixed to the ball and socket joint body, asleeve which forms a central chamber and which has at both its ends arespective internal perimetral retaining projection and seat.

According to the above mode of embodiment of the retaining means andseat, the internal perimetral projections are characterized in that theyhave a cross section of general interior-oriented sawtooth outline, sothat entry of the ball into the central chamber is implemented by theapplication of a force in the direction given by the longitudinal axisof the chamber to produce elastic deformation of the correspondingprojection, that force being lower in intensity than the contrary forcewhich has to be applied, once the ball is situated in the centralchamber, to produce elastic deformation of the corresponding projectionand withdraw the ball from the chamber.

According to a second mode of embodiment, the retaining and seat meansare characterized in that they include, coaxially arranged with respectto the transverse passage and fixed to the ball and socket joint body,two superimposed sleeves, a first and second sleeve respectively, inwhich the first sleeve acts as a shock absorber and the second sleeveforms the central chamber and at both its ends a respective plurality ofcoplanar sectoral retaining and seat projections, preferably three innumber, situated with those on one side alternating in position withthose on the other.

According to the above mode of embodiment of the retaining and seatmeans, each coplanar sectoral projection is characterized in that it hasa cross section of general interior-oriented sawtooth outline, so thatentry of the ball into the central chamber is implemented by theapplication of a force in the direction given by the longitudinal axisof the chamber to produce elastic deformation of the correspondingcoplanar sectoral projections, that force being lower in intensity thanthe contrary force which has to be applied, once the ball is situated inthe central chamber, to produce elastic deformation of the correspondingcoplanar sectoral projections and withdraw the ball from the chamber.

The above-described characteristics of the ball and socket joint bodyfor terminals of control cables of the invention, provide an innovativesolution to the disadvantages presented by the known embodiments of balland socket joint body in which coupling with the ball of thearticulation is implemented on one side only. Indeed, the fact that theball and socket joint body of the invention includes a passage which istransverse with respect to the longitudinal axis of the means ofcoupling with the steel cable, forming two inlet mouths of freelychoosable alternative use, greatly facilitates the operations ofcoupling with the ball of the articulation, since said coupling can beimplemented through either of said inlet mouths to leave the ball firmlyhoused in a central chamber. Moreover, the characteristic retainingmeans and seat with which the central chamber of the ball and socketjoint body is provided permit the intensity of the forces to be appliedfor coupling and uncoupling of the ball and socket joint body with andfrom the ball of the articulation to be equal or different in functionof the needs arising in each specific case of application; that is, oneof the options, the one which the first and second modes of embodimentof the retaining means and seat render possible, consists in theintensities of the coupling and uncoupling forces being different, andspecifically the intensity of the uncoupling force is substantiallygreater than that of the coupling force, this arrangement having thepurpose, firstly, of facilitating entry of the ball of the articulationinto the central chamber of the ball and socket joint body and,secondly, ensuring that under normal working conditions the ball of thearticulation cannot come out of the central chamber, while another ofthe options, that which the third and fourth embodiments of theretaining means and seat render possible, consists in the intensity ofthe coupling force being equal to that of the uncoupling force, saidforce being of an intensity such that, when the ball is situated in thecentral chamber and under normal working conditions, it prevents theball being able to come out of the central chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawing sheets of the present specification show the ball and socketjoint body for terminals of control cables of the invention. In saiddrawings:

FIG. 1 is a longitudinal section view of a first mode of embodiment R1of the ball and socket joint body of the invention;

FIG. 2 is a perspective view of the mode of embodiment R1 shown in FIG.1;

FIG. 3 is a longitudinal section view of a second mode of embodiment R2of the ball and socket joint body of the invention;

FIG. 4 is a perspective view of the mode of embodiment R2 shown in FIG.3;

FIG. 5 is a longitudinal section view of a third mode of embodiment R ofthe ball and socket joint body of the invention;

FIG. 6 is a plan view of the mode of embodiment R3 shown in FIG. 5;

FIG. 7 is a cross-section view of the mode of embodiment R3 shown inFIGS. 5 and 6;

FIG. 8 is a perspective view of the mode of embodiment R3 of the balland socket joint body of the invention shown in FIGS. 5, 6 and 7;

FIG. 9 is a longitudinal section view of a fourth mode of embodiment R4of the ball and socket joint body of the invention;

FIG. 10 is a cross-section view of the mode of embodiment R4 shown inFIG. 9;

FIG. 11 is a plan view of the mode of embodiment R4 shown in FIGS. 9 and10, and

FIG. 12 is a perspective view of the mode of embodiment R4 shown inFIGS. 9, 10 and 11.

DESCRIPTION OF A PREFERRED EMBODIMENT

The figures of the drawing sheets show four modes of embodiment,indicated as R1, R2, R3 and R4, of the ball and socket joint body forterminals of control cables of the invention; FIGS. 1 and 2 show thefirst mode R1, FIGS. 3 and 4 the second mode R2, FIGS. 5 to 8 the thirdmode R3, and FIGS. 9 to 12 the fourth mode R4. All the modes ofembodiment R1, R2, R3 and R4 are applicable to a control cable, made upessentially of a sheathed steel cable, of which, for the purposes ofgreater clarity of outline, only a metal rod 1 has been shown, which,fixed to the corresponding end of the steel cable, forms at its free enda coupling extension 2 shown in FIGS. 1, 3, 5 and 9.

The modes of embodiment R1 and R2 use a same general configuration ofthe ball and socket joint body, marked with reference number 3, whilethe modes of embodiment R3 and R4 use in their turn also a same generalconfiguration of the ball and socket joint body which is different fromthe previous embodiment and is marked with reference number 19; it isunderstood that, as stated above, the ball and socket joint body canadopt any configuration suited to each specific case of applicationwithout the essential nature of the invention being affected thereby,and that the ball and socket joint bodies 3, 19 shown in the figures ofthe drawing sheets are given solely by way of illustrative example. Inthe description which follows of the modes of embodiment R1 and R2, theparts common to both embodiments share the same reference numbers, andthe same criterion is applied in description of the modes of embodimentR3 and R4.

The modes of embodiment R1, R2, R3 and R4 of the ball and socket jointbody of the invention are designed to be coupled to a ball 13, shown bymeans of broken lines in FIGS. 1, 3, 7 and 10 of the drawing sheets,attached to an actuating control which, for the same reasons asindicated above, is not shown.

FIGS. 1 and 2 show how the mode of embodiment R1 comprises a ball andsocket joint body 3 of essentially elongated parallelepiped shape inwhich, longitudinally, an extension 4 can be observed on which duringmanufacturing of the ball and socket joint body 3 the coupling extension2 of the rod 1 is included. FIG. 1 shows how, transversally arrangedwith respect to the longitudinal axis of the rod 1, the ball and socketjoint body 3 has a passage 5 which forms two equal inlet mouths A1 andB1, respectively. Coaxially arranged with respect to the transversepassage 5 there is a sleeve 6 of elastic material and of hollow generalcylindrical shape on both ends of which, which ends are open, there is arespective internal perimetral retaining projection 7 and seatsymmetrically situated with respect to the main theoretical transverseplane of the transverse passage 5. For securing of the sleeve 6, theball and socket joint body 3 has, at one of the ends of the transversepassage 5, the end corresponding to inlet mouth A1, an annularprojection 8 which works by way of seat and on which there rests thesleeve 6, while at its other end, the end corresponding to inlet mouthB1, there is a detachable cover 9 which can be coupled to the ball andsocket joint body (3) by means of respective and complementary securingopenings 10 and projections 11.

FIG. 1 shows how the sleeve 6 forms a central chamber 12 which,delimited by the two internal perimetral projections 7 for retaining andseating, is designed to receive the ball 13 with a close fit. In FIG. 1,the ball 13 is inserted into the central chamber 12 by traversing mouthA1; it can be understood that given the symmetry of the transversepassage 5, the ball 13 could be inserted into the central chamber 12either through inlet mouth A1 or inlet mouth B1.

The internal perimetral projections 7 for retaining and seating have across section of sawtooth outline oriented inwards, as shown in FIG. 1.With this configuration of the projections 7, entry of the ball 13 intothe central chamber 12, for example through mouth A1 as shown in FIG. 1,requires the application of a force F1 in the direction given by thelongitudinal axis of the central chamber 12 of an intensity sufficientto overcome the elastic reaction of the corresponding perimetralprojection 7, with the force F1 being lower in intensity than thecontrary force F1' which has to be applied so that, once the ball 13 issituated in the chamber 12, it can then be withdrawn.

FIGS. 3 and 4 show how the mode of embodiment R2 comprises a ball andsocket joint body 3 which, as in mode of embodiment R1, includes thecoupling extension 2 of the rod 1. FIG. 3 shows how, transversallyarranged with respect to the longitudinal axis of the rod 1, the balland socket joint body 3 has a passage 18 which forms two equal inletmouths A2 and B2, respectively. Coaxially arranged with respect to thetransverse passage 18 there are two sleeves, a first sleeve 14 andsecond sleeve 15, respectively, superimposed on each other. The firstsleeve 14 is of elastic material and acts as a shock absorber, while thesecond sleeve 15 is of elastic material of greater hardness than that ofthe first sleeve 14; both sleeves 14, 15 are of hollow generalcylindrical shape open at both their ends, the second sleeve 15 formingat each end three coplanar sectoral projections 16 for retaining andseating regularly distributed and symmetrically arranged with respect tothe main theoretical transverse plane of the transverse passage 18, withthe coplanar sectoral projections 16 of both ends being situated inalternating positions. As described above for the mode of embodiment R1,both sleeves 14, 15 are secured to the ball and socket joint body 3 bymeans of the annular projection 8 and the detachable cover 9.

FIG. 3 shows how the second sleeve 15 forms a central chamber 17 which,delimited by the coplanar sectoral projections 16, is designed toreceive the ball 13 with a close fit. In FIG. 3, the ball 13 is insertedinto the central chamber 17 by traversing mouth A2; it can be understoodthat given the symmetry of the transverse passage 18, the ball 13 couldbe inserted into the central chamber 17 either through inlet mouth A2 orinlet mouth B2.

Each coplanar sectoral projection 16 has a cross section of sawtoothoutline oriented inwards, as shown in FIG. 3. With this configuration ofthe projections 16, entry of the ball 13 into the central chamber 17,for example through mouth A2 as shown in FIG. 3, requires theapplication of a force F2 in the direction given by the longitudinalaxis of the central chamber 12 of an intensity sufficient to overcomethe elastic reaction of the corresponding coplanar sectoral projections16, with the force F2 being lower in intensity than the contrary forceF2' which has to be applied so that, once the ball 13 is situated in thechamber 17, it can then be withdrawn.

I claim:
 1. A ball and socket joint for coupling an end of controlcables with a terminal, comprising a ball member; and a ball and socketjoint body including a metal rod having a longitudinal axis, a passageextending transversely to said longitudinal axis and having two oppositeinlet mouths and a chamber for receiving said ball member; andelastically deformable retaining and seat means formed so that said ballcan be introduced into and extracted freely from said chamber throughone or other of said inlet mouths by double elastic deformation of saidretaining and seat means, said elastically deformable retaining and seatmeans including two superposed sleeves which form a cylindrical seat andare coaxially arranged with respect to said transverse passage, a firstone of said sleeves being formed as a shock absorber while a second oneof said sleeves forming said chamber and having two opposite ends eachprovided with a plurality of coplanar sectorial retaining and seatprojections so that positions of said projections at one of said endsalternates with positions of said projections at the other of said ends.2. A ball and socket as defined in claim 1, wherein said second sleeveis provided with three retaining and seat projections.
 3. A ball andsocket as defined in claim 1, wherein each of said projections has across-section of interior-oriented saw tooth outline, so that entry ofsaid ball into said chamber is implementable by application of a forceproducing elastic deformation of a corresponding one of said projectionsand being lower than an opposite force which has to be applied, oncesaid ball is situated in said chamber, to produce elastic deformation ofthe other of said projections for withdrawal of said ball from saidchamber.